AuthorTopic: Antifreeze: Which type is best? (Read 655 times)

I've read a couple dozen threads on these topics. Since all are a year old or more, I'll start a new one to add my questions and comments:

Engine coolant

Obviously MaineSail hates "Death cool", so that's out of the running. Everything I've found on this site says to use "ordinary Prestone". I don't know what the PO put in my boat, but since it was "green stuff" I topped off the reservoir with 50% Prestone Extended Life for the last couple of years, since they emphasize its compatibility with other brands/types. It's worked fine so far. But I've changed my freshwater pump this winter, and plan to flush/rinse/clean/rinse/refill my system in the spring. I want to use the right thing going forward. I was planning to use Prestone again because it's is so widely available everywhere, and I don't want to be driving an hour to get matching antifreeze if I'm in a remote area and need to top off.

However, I am also aware of Practical Sailor's Oct 2014 article that urged the use of heavy duty antifreezes that have anti-cavitation inhibitors that will prevent cavitation pitting. Drew Frye did the testing and repeated his recommendations over on Sailnet recently:

Among his recommended brands, Zerex G05 seems to be the most widely available, and very reasonably priced. But I see no mention of it here. Is there a reason for that? If you read the article, it seems that the problem is worst for engines with thin-walled wet sleeve liners, presumably because their thinness causes them to "ring" (like a bell) and thus drive the cavitation which enhances corrosion. (Anyone who plays a brass instrument knows that thin metals ring more than thick ones.) Does anyone here know if Universal employed thin wet sleeve liners in their designs? Or is this just a Yanmar problem?

I'd like to hear your comments.

Raw/potable water antifreeze

In reviewing most of the comments about this, I saw some concerns over damage to rubber parts like impellers, gaskets, and joker valves. I agree with the general comments that these parts are not damaged by antifreezes based on propylene glycol or ethylene glycol. However, EG is very toxic and cannot be released into waterways or watersheds, and impellers' lives will be shortened somewhat by being left compressed in the cam all winter even with glycols present.

However, some people also referred to using RV antifreeze, so I thought I'd repeat Maine Sail's warning that the cheap orange RV antifreeze uses ethanol in the formula, which will leach the plasticizers out of synthetic rubbers, causing them to harden and crack over time. Also, the denaturing agents that the Feds require to be included with the ethanol will cause a bitter taste in your potable water system that could take years to clean out (as I have learned after my PO used the orange stuff in our potable water tanks). So make sure to use the pink stuff (not orange) and read the label to ensure it does not say "combustible", as that's a giveaway that ethanol is present.

BA for what it's worth, take a look at (Peak Brand) Sierra safe (well, safe-er) AF.

As far as pink stuff, and there will surely be those who disagree -- it's a conspiracy between marine suppliers and yards and boating magazines and mechanics. Why pump that stuff when you can easily evacuate all the H2O (that matters) from the cooling train and potable lines? A waste of good beer money. Why worry about a diluted concentration, and refractometers and/or catching exhaust and checking freeze point - because it's how they make a living. Just spend the time to get rid of the stuff that freezes.

If you use PG, a refractometer is gilding, you can get a PG (just like) EG tester (Amazon or Autozone online, not in the stores.) Or use an EG tester and the conversion chart (find it online) -- just mark your tester for PG freeze temps or use the cheat sheet -- e.g., specific gravity X = freeze temp Y for EG AF, or = freeze point Z for PG AF.

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Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.So throw off the bowlines. Sail away from the safe harbor. Catch the tradewinds in your sails.Explore. Dream. Discover. -Mark Twain

As far as pink stuff, and there will surely be those who disagree -- it's a conspiracy between marine suppliers and yards and boating magazines and mechanics. Why pump that stuff when you can easily evacuate all the H2O (that matters) from the cooling train and potable lines? A waste of good beer money. Why worry about a diluted concentration, and refractometers and/or catching exhaust and checking freeze point - because it's how they make a living. Just spend the time to get rid of the stuff that freezes.

Ken,

If you did this for a living, on a larger scale, you would be chuckling at yourself for the above statement. My own boat gets AF in both domestic and engine systems and she is parked a just few feet from an 80 gallon Ingersol Rand industrial air compressor that runs a massive bead blast cabinet continuously without breaking a sweat.

Why? Because "blowing lines out" or "draining" is not a consistently reliable method, especially in complicated plumbing systems. Every spring we get more work from folks who read advice like yours, and follow it, than we do from folks who used AF to winterize. I had one guy about 8 years ago who attempted this with a 12V outlet powered "air compressor".... After drilling out about 80 bungs, fixing leaks, replacing pumps etc. he was staring at a $1200.00 bill. We do still get folks who only spend $8.00 on AF, instead of $12.00, but we see far more systems with cracked fittings from being blown or drained than we do from systems that get AF. The larger the boat the more complicated the plumbing systems.

I've read a couple dozen threads on these topics. Since all are a year old or more, I'll start a new one to add my questions and comments:

Engine coolant

Obviously MaineSail hates "Death cool", so that's out of the running.

Dex-Cool was reformulated but our engine came from the factory with the old stuff, when shipped from WB. It caused it to sludge up very badly. These days I use a diesel specific antifreeze and have been using Rotella Ultra ELC for many years. I change it annually and it is inexpensive, about $1 - $2 more than a typical auto coolant, and I can get it locally.

Be careful however, as you do not want to mix coolants unless the bottle says something to the effect of; "all makes all models". Peak, Prestone, NAPA etc. all have an "all makes all models" coolant. If you don't know what coolant you have it is best to use one that can be mixed with any existing coolant. Most older sailboat diesels I come across are using a "green" coolant except for Yanmar, and some other newer engines that use a HD type, which is usually red/pinkish. When I switched out the Dex-Cool I had to run a full Rydlyme purge, then flush the engine, then make the switch to an HD coolant which has been Rotella Ultra ELC.

Don't even get me started on the local diesel mechanic who went around switching all his customers to a PG "green" engine coolant, not marking the engines as such, then boat yards & owners were adding green EG to the green PG.... Talk about an $$$$$$$ oops....

I share the concerns over "blowing out" water lines with air. Air does not displace water very well when pushing "uphill". It will bubble through and the water will just fall back to the low point (where it does its damage upon freezing). In theory you could have a real big compressor that "blasts" it all away, but the pressure needed to do that could do some damage also. I just spend the money on pink antifreeze, drain as many low points as I can easily reach (to minimize dilution), and then pump it in. As an extra dose of safety, after pumping in the antifreeze, I pull the HX anode to re-drain it, and also drain the aqua-lift muffler. My air conditioner is particularly tricky to winterize because the water loop is oriented vertically, so there's a LOT of residual water that DOES NOT blow out. (I try to blow out as much as I can to minimize dilution.)

Regarding engine antifreeze, I'm really looking for comments whether the "yellow" G-05 HOAT antifreeze type offers benefits with the Westerbeke motors, or I should just stick with normal green stuff with traditional IAT corrosion inhibition. The Practical Sailor tests were eye-opening. But I also expect that when switching from one type to the other, a complete flush is absolutely essential to avoid inter-mixing, and with all the bypass loops (hot water heater, thermostat bypass, etc) getting a complete flush can be trickier than it seems.

Regarding engine antifreeze, I'm really looking for comments whether the "yellow" G-05 HOAT antifreeze type offers benefits with the Westerbeke motors, or I should just stick with normal green stuff with traditional IAT corrosion inhibition. The Practical Sailor tests were eye-opening. But I also expect that when switching from one type to the other, a complete flush is absolutely essential to avoid inter-mixing, and with all the bypass loops (hot water heater, thermostat bypass, etc) getting a complete flush can be trickier than it seems.

I think any diesel engine can benefit from an HD (diesel) type coolant but I have yet to see a small sailboat AUX motor die from cavitation issues. I do know that the manufacturer of the block on our Westerbke recomends an HD type coolant yet WB does not specify this.

In your situation, if you don't know for 100% what is in there now, you essentially have two choces;

1- Use an "all makes all models" automotive coolant that can be mixed with what ever you have.2- Flush the engine and start over.

If starting over it really makes little financial sense not to use an HD diesel type coolant.

I share the concerns over "blowing out" water lines with air. Air does not displace water very well when pushing "uphill".

As always there's no single answer that fits each and every boat/each and every scenario/each and every climate. I too did the pink routine for 2-3 years before I got to the point to put the effort into locating where I could gravity drain with no residual water and if necessary putting a port there. And blow the lines for good measure (no, not uphill you are correct.) If that's not possible in your case, then sure, more caution is better than less.

It's still a conspiracy for suppliers to forth the notion that there is one and only one way to winterize and that's to use their pink stuff product. There are different ways to skin cats -- sometimes it takes ingenuity to move outside the proverbial box, or sometimes it's maintaining the same routine here, but over there using a different routine that's better/cheaper/quicker/whatever-er. That's what "engineered solutions" is all about! It's all what the individual owner feels comfortable handling.

I haven't bought pink stuff since 1995, and no apocalypse yet. And that includes Buffalo NY winters!!

There was only one time -- and it had nothing to do with pink or no pink (I drained, didn't pink the WH) it was timing. I wasn't supposed to be pulled yet but was (this yard did whatever it cared to, whenever it cared to) and went on the hard before I got to drain the WH -- we had a sudden overnight cold snap and split a fitting. Only because the WH is "exposed" on the C30 mk-1. If it was below as all y'alls are, I would have been fine. After that -- and that they beat the hell out of my boat tied to a steel piling w/no fenders, lost my grill overboard in the Bflo river, and hit my bow rail w/ another boat -- they were history.

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Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.So throw off the bowlines. Sail away from the safe harbor. Catch the tradewinds in your sails.Explore. Dream. Discover. -Mark Twain

Sometimes, pink, green, or purple stuff just doesn't fix "stupid." But that's not a fair measure, eh? I know folks who can't use a cable cutter w/o knicking every strand, but that doesn't mean that no one out there can make their own cables and have to hire a profssional. If they can't reliably drain, then don't drain.

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Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.So throw off the bowlines. Sail away from the safe harbor. Catch the tradewinds in your sails.Explore. Dream. Discover. -Mark Twain

"it's a conspiracy between marine suppliers and yards and boating magazines and mechanics."Ken,Could you provide some documentation for this conspiracy theory? This evidence should also include RVs, cottages etc.Paul

<<using Rotella Ultra ELC for many years. I change it annually and it is inexpensive, about $1 - $2 more than a typical auto coolant, and I can get it locally>>>

I see Tractor Supply carries Rotella ELC , but not the Ultra. Cannot seem to locate the ultra at a reasonable cost -- I see it on amazon, elsewhere (w/ rediculous shipping costs.) No autozone, Pep Boys, etc. Any other sources anyone has found?

-k

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Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.So throw off the bowlines. Sail away from the safe harbor. Catch the tradewinds in your sails.Explore. Dream. Discover. -Mark Twain

My local NAPA has it and we have a wholesale account there. The price shown on-line is a retail price. I would suspect that most NAPA's can get it because they cater to fleet, municipalities etc... I only chose it because it meets the Mitsubishi requirement and my engine block is a Mitsubishi not really a Westerbeke. Since converting to Rotella Ultra ELC I have had zero sludge issues but this is not to say that another diesel grade coolant would not perform the same or similarly.

Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.So throw off the bowlines. Sail away from the safe harbor. Catch the tradewinds in your sails.Explore. Dream. Discover. -Mark Twain

I notice that a few manufacturers have a heavy-duty PG antifreeze recommended for diesels. Cummins is one, Zerex another.One reason I like the idea of PG is for the water heater. If a pinhole develops, there's a slight chance that engine coolant can leach into the potable system (typically it would be the opposite direction.) I don't know what concentration of EG would be toxic, but PG would be safer during a period until the leak is discovered.

Note that while OSHA lists PG as generally safe, at least four states list it as a hazardous substance, and Canada WHMIS classifies it as D3 (the same class as asbestos, mercury, saccharin.) hmmmmmm.. Is pink stuff available in Canada for use in water systems? Maybe someday we'll find it isn't as safe as we think for potable systems?

« Last Edit: February 17, 2019, 07:33:05 PM by KWKloeber »

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Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.So throw off the bowlines. Sail away from the safe harbor. Catch the tradewinds in your sails.Explore. Dream. Discover. -Mark Twain